Photosensitized degradation of Irgarol 1051 in water

Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) is a herbicide analogue that is added to antifouling agents used on ships. Our former study on its degradation in sunlight suggested that unknown photosensitizers in natural waters accelerated the photodegradation to the degradation product, M1. In this study, the photodegradation of Irgarol in water was investigated in the presence of some photosensitizers. Test water containing Irgarol or M1, with or without photosensitizers, was irradiated with light from a UV-A fluorescent lamp for 48h. The concentrations of Irgarol and M1 in the test water were determined by HPLC after solid-phase extraction. M1 was more stable than Irgarol when irradiated in the presence of photosensitizers such as acetone, benzophenone, tryptophan, and rose bengal. Hydrogen peroxide (HP) accelerated the photodegradation of Irgarol, and the product M1 was degraded in the presence of more than 100mgl(-1) HP after 10h. Natural humic substances (NHS) also accelerated the photodegradation of Irgarol, but in this case, the product M1 persisted even when Irgarol was completely degraded. Photosensitized degradation of Irgarol by NHS may result in the accumulation of M1 in aquatic environments.     

Levels of antifoulant Irgarol 1051 in the Conwy Marina, North Wales

Irgarol 1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) is an antifouling agent used in paint formulations that are applied to the hulls of ships. A survey was carried out at Conwy Marina in North Wales to determine the levels of the herbicide over a period of three months. Liquid/liquid extraction was used to concentrate the analyte for quantitative analysis using gas chromatography/mass spectrometry (GC/MS) in the selected ion monitoring (SIM) mode. The concentrations of Irgarol 1051 in Conwy marina ranged from 7 to 543 ng/l, similar to the levels found in many other marinas, estuaries and ports in England, although much lower than those in C?te d'Azur, France. The concentrations of Irgarol 1051 were not found to be influenced by salinity, pH or temperature, although there is a strong correlation between the average concentrations of Irgarol 1051 and the density of boating activity. At the levels found in the marina, it is possible that non-target photosynthetic inhibition could occur.     

Assessment of the risk posed by the antifouling booster biocides Irgarol 1051 and diuron to freshwater macrophytes

Antifouling paints are used to reduce the attachment of living organisms to the submerged surfaces of ships, boats and aquatic structures, usually by the release of a biocide. Two 'booster' biocides in common use are the triazine herbicide Irgarol 1051 (N-2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine), and diuron (1-(3,4-dichlorophenyl)-3,3-dimethylurea), which are designed to inhibit algal photosynthesis. Previous research has been directed at the effects of these compounds in marine and estuarine environments. In 2001 we sampled the main rivers and shallow freshwater lakes (Broads) of East Anglia UK for Irgarol 1051, its metabolite GS26575 (2-methylamino-4-tert-butylamino-6-amino-s-triazine) and diuron in order to establish the baseline environmental concentrations of these compounds in freshwater systems of eastern UK and to investigate their possible effects on aquatic plants. Irgarol 1051, GS26575 and diuron were found in water samples collected from 21 locations. The highest concentrations were found in the Norfolk and Suffolk Broads in May. The rivers Great Ouse, Wissey, Bure and Yare also contained all three compounds, as did the Great Ouse Cut-off Channel. The toxicity of these biocides to three macrophyte species (Apium nodiflorum, Chara vulgaris, and Myriophyllum spicatum) was investigated. Deleterious effects on relative growth rate, the maximum quantum efficiency (Fv/Fm) of photosystem II and, for Apium, root mass production were found. C. vulgaris was generally most sensitive; growth, especially of roots, was strongly affected in A. nodiflorum; growth rate of M. spicatum was sensitive to diuron. No observed effect concentrations (NOEC) were interpolated using standard toxicological analysis. These were compared with measured environmental concentrations (MEC) to determine the ranges of risk quotients (MEC/NOEC). Both Irgarol 1051 and diuron represented significant risks to A. nodiflorum and C. vulgaris in this area.     

Photodegradation of the antifouling compounds Irgarol 1051 and Diuron released from a commercial antifouling paint

The antifouling compound Irgarol 1051 and its degradation product M1 (also known as GS26575), along with another antifouling compound Diuron, have recently been found in Japanese coastal waters. This study was undertaken to find the origin of these chemicals and investigate their aquatic fate. Five glass plates, each coated with 1 g of antifouling paint containing Irgarol and Diuron, were submerged in 250 ml of five different test waters and the plates removed after several months. The aqueous solutions were divided into two groups: one exposed to natural sunlight, and the other kept in the dark as a control. Irgarol and Diuron were detected in all aqueous solutions, suggesting leaching from antifouling paints is the origin of these antifouling biocides found in Japanese coastal waters. Under sunlight conditions, Irgarol underwent a rapid degradation to produce M1, which remained even after Irgarol had disappeared from the system. These compounds were persistent in any aqueous solutions tested under dark conditions, indicating high stability to hydrolysis. Diuron and M1 were more persistent than Irgarol under sunlight irradiation. Since these compounds have high herbicidal activities, their ultimate impact on aquatic ecosystems is closely related to their aquatic fate.     

A study of the partitioning behavior of Irgarol-1051 and its transformation products

Partitioning behavior of the antifouling booster biocide, Irgarol-1051 (2-methythio-4-tert-butylamino-6-cyclopropylamino-s-triazine), its production by-product, M3, and its environmental transformation products, M1 and M2, were studied. Octanol-water partition coefficients, log K(OW), and organic matter-water partition coefficients, log K(OC), of these s-triazines were measured by reversed-phase HPLC and a triphasic SPME equilibrium model, respectively. The average log K(OW) (+/-SD) of the four s-triazine species were: 4.39+/-0.07 (M3); 3.38+/-0.12 (Irgarol-1051); 2.92+/-0.12 (M2) and 2.54+/-0.11 (M1), while mean log K(OC) (+/-SD) of these species were: 2.47+/-0.03 (M3); 2.16+/-0.03 (Irgarol-1051); 1.97+/-0.03 (M2) and 1.79+/-0.04 (M1). These results were compared to reported physicochemical parameters of Irgarol-1051 in the literature. Partitioning behavior of these s-triazine species in the coastal environment revealed by their K(OW) and K(OC) were also discussed.     

The effect of resuspending sediment contaminated with antifouling paint particles containing Irgarol 1051 on the marine macrophyte Ulva intestinalis

The effect of resuspending sediment contaminated with Irgarol 1051 based antifouling paint particles on the green macroalga Ulva intestinalis was examined. U. intestinalis was also exposed to sediment spiked with Irgarol 1051. The macroalga were exposed over 21 days to the resuspension of sediments containing 61.2 mg kg(-1) of antifouling paint particles containing Irgarol 1051 that provided aqueous Irgarol 1051 concentrations of approximately 0.3 microg l(-1), Irgarol 1051 and appropriate controls. The growth response was compared with that for 'clean' sediment. Resuspension of sediment was associated with reduced growth when compared to seawater alone. Resuspension of sediment spiked with Irgarol 1051 was associated with a greater reduction in growth, with growth being significantly reduced when sediment containing antifouling paint particles was resuspended. The data suggest that the prolonged disturbance of sediments containing antifouling paint particles in marinas represents a potential and as yet unquantified hazard to photosynthetic organisms.     

Immunotoxicity in ascidians: antifouling compounds alternative to organotins: III--the case of copper(I) and Irgarol 1051

After the widespread ban of TBT, due to its severe impact on coastal biocoenoses, mainly related to its immunosuppressive effects on both invertebrates and vertebrates, alternative biocides such as Cu(I) salts and the triazine Irgarol 1051, the latter previously used in agriculture as a herbicide, have been massively introduced in combined formulations for antifouling paints against a wide spectrum of fouling organisms. Using short-term (60 min) haemocyte cultures of the colonial ascidian Botryllus schlosseri exposed to various sublethal concentrations of copper(I) chloride (LC₅₀ = 281 μM, i.e., 17.8 mg Cu L⁻¹) and Irgarol 1051 (LC₅₀ > 500 μM, i.e., >127 mg L⁻¹), we evaluated their immunotoxic effects through a series of cytochemical assays previously used for organotin compounds. Both compounds can induce dose-dependent immunosuppression, acting on different cellular targets and altering many activities of immunocytes but, unlike TBT, did not have significant effects on cell morphology. Generally, Cu(I) appeared to be more toxic than Irgarol 1051: it significantly (p < 0.05) inhibited yeast phagocytosis at 0.1 μM (∼10 μg L⁻¹), and affected calcium homeostasis and mitochondrial cytochrome-c oxidase activity at 0.01 μM (∼1 μg L⁻¹). Both substances were able to change membrane permeability, induce apoptosis from concentrations of 0.1 μM (∼10 μg L⁻¹) and 200 μM (∼50 mg L⁻¹) for Cu(I) and Irgarol 1051, respectively, and alter the activity of hydrolases. Both Cu(I) and Irgarol 1051 inhibited the activity of phenoloxidase, but did not show any interactive effect when co-present in the exposure medium, suggesting different mechanisms of action.     

Comparison of the ecotoxicological impact of the triazines Irgarol 1051 and atrazine on microalgal cultures and natural microalgal communities in Lake Geneva

The antifouling herbicide Irgarol 1051 has been detected in recent years in numerous estuaries, marinas, harbors and coastal areas, and in some harbors on Lake Geneva, but so far only a few studies have investigated the ecotoxicological effects of this compound on microalgae. The purpose of this study was to assess the ecotoxicological impact of Irgarol 1051 on the algal communities of Lake Geneva, and to compare its phytotoxicity to that of the common triazine herbicide, atrazine. We investigated the response of phytoplanktonic and periphytonic algal communities and single-species isolates collected from the lake, to the PS II inhibitor Irgarol 1051 (growth, proxy of photosynthetic activity and community structure). A short-term bioassay was developed based on in vivo fluorescence, together with nanocosm experiments with natural algal communities, and single-species tests on algal strains isolated from the lake. The toxicity of Irgarol 1051 towards periphyton and phytoplankton was shown to be higher than that of atrazine. Indications of the tolerance induced by this triazine in the algal communities of Lake Geneva, suggests that even at the levels of contamination reported in some parts of the lake, Irgarol 1051 is already exerting selection pressure. Information about sensitivities, selection and tolerance from laboratory experiments are used to explain the observations in natural microalgal communities from the lake.     

Antifouling paint booster biocide contamination in Greek marine sediments

Organic booster biocides were recently introduced as alternatives to organotin compounds in antifouling products, after restrictions imposed on the use of tributyltin in 1987. In this study, the concentrations of three biocides commonly used as antifoulants, Irgarol 1051 (2-methylthio-4-tertiary-butylamino-6-cyclopropylamino-s-triazine), dichlofluanid (N-dichlorofluoromethylthio-N',N'-dimethyl-N-phenyl sulphamide) and chlorothalonil (2,4,5,6-tetrachloro isophthalonitrile) were determined in sediments from ports and marinas of Greece. Piraeus (Central port, Mikrolimano and Pasalimani marinas), Thessaloniki (Central port and marina), Patras (Central port and marina), Elefsina, Igoumenitsa, Aktio and Chalkida marinas were chosen as representative study sites for comparison with previous monitoring surveys of biocides in coastal sediments from other European countries. Samples were collected at the end of one boating season (October 1999), as well before and during the 2000 boating season. All the compounds monitored were detected at most of sites and seasonal dependence of biocide concentrations were found, with maxima during the period June-September, while the winter period (December-February) lower values were encountered. The concentrations levels ranged from 3 to 690 ng/g dw (dry weight). Highest levels of the biocides were found in marinas (690, 195 and 165 ng/g dw, for Irgarol, dichlofluanid and chlorothalonil respectively) while in ports lower concentrations were observed. Antifouling paints are implicated as the likely sources of biocides since agricultural applications possibly contributed for chlorothalonil and dichlofluanid inputs in a few sampling sites.     

Risk assessment of herbicides and booster biocides along estuarine continuums in the Bay of Vilaine area (Brittany, France)

A 2-year study was implemented to characterize the contamination of estuarine continuums in the Bay of Vilaine area (NW Atlantic Coast, Southern Brittany, France) by 30 pesticide and biocide active substances and metabolites. Among these, 11 triazines (ametryn, atrazine, desethylatrazine, desethylterbuthylazine, desisopropyl atrazine, Irgarol 1051, prometryn, propazine, simazine, terbuthylazine, and terbutryn), 10 phenylureas (chlortoluron, diuron, 1-(3,4-dichlorophenyl)-3-methylurea, fenuron, isoproturon, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl)-urea, linuron, metoxuron, and monuron), and 4 chloroacetanilides (acetochlor, alachlor, metolachlor, and metazachlor) were detected at least once. The objectives were to assess the corresponding risk for aquatic primary producers and to provide exposure information for connected studies on the responses of biological parameters in invertebrate sentinel species. The risk associated with contaminants was assessed using risk quotients based on the comparison of measured concentrations with original species sensitivity distribution-derived hazardous concentration values. For EU Water Framework Directive priority substances, results of monitoring were also compared with regulatory Environmental Quality Standards. The highest residue concentrations and risks for primary producers were recorded for diuron and Irgarol 1051 in Arzal reservoir, close to a marina. Diuron was present during almost the all survey periods, whereas Irgarol 1051 exhibited a clear seasonal pattern, with highest concentrations recorded in June and July. These results suggest that the use of antifouling biocides is responsible for a major part of the contamination of the lower part of the Vilaine River course for Irgarol 1051. For diuron, agricultural sources may also be involved. The presence of isoproturon and chloroacetanilide herbicides on some dates indicated a significant contribution of the use of plant protection products in agriculture to the contamination of Vilaine River. Concentration levels and associated risk were always lower in estuarine sites than in the reservoir, suggesting that Arzal dam reduces downstream transfer of contaminants and favors their degradation in the freshwater part of the estuary. Results of the additional monitoring of two tidal streams located downstream of Arzal dam suggested that, although some compounds may be transferred to the estuary, their impact was probably very low. Dilution by marine water associated with tidal current was also a major factor of concentration reduction. It is concluded that the highest risks associated to herbicides and booster biocides concerned the freshwater part of the estuary and that its brackish/saltwater part was exposed to a moderate risk, although some substances may sometimes exhibit high concentration but mainly at low tide and on an irregular basis.     

Degradation of CL-20 by white-rot fungi

In previous studies, we found that the emerging energetic chemical, CL-20 (C6H6N12O12, 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane), can be degraded following its initial denitration using both aerobic and anaerobic bacteria. The C and N mass balances were not determined due to the absence of labeled starting compounds. The present study describes the degradation of the emerging contaminant by Phanerochaete chrysosporium using ring-labeled [15N]-CL-20 and [14C]-CL-20. Ligninolytic cultures degraded CL-20 with the release of nitrous oxide (N2O) in amounts corresponding to 45% of the nitrogen content of CL-20. When ring-labeled [15N]-CL-20 was used, both 14N14NO and 15N14NO were observed, likely produced from -NO2 and N-NO2, respectively. The incubation of uniformly labeled [14C]-CL-20 with fungi led to the production of 14CO2 (> 80%). Another ligninolytic fungus, Irpex lacteus, was also able to degrade CL-20, but as for P. chrysosporium, no early intermediates were observed. When CL-20 was incubated with manganese peroxidase (MnP), we detected an intermediate with a [M-H]- mass ion at 345 Da (or 351 and 349 Da when using ring-labeled and nitro-labeled [15N]-CL-20, respectively) matching a molecular formula of C6H6N10O8. The intermediate was thus tentatively identified as a doubly denitrated CL-20 product. The concomitant release of nitrite ions (NO2-) with CL-20 degradation by MnP also supported the occurrence of an initial denitration prior to cleavage and decomposition.     

Toxicity evaluation of new antifouling compounds using suspension-cultured fish cells

A simple, rapid toxicity test was developed using the suspension-cultured fish cell line CHSE-sp derived from chinook salmon Oncorhynchus tshawytscha embryos in order to assess the toxicity of new marine antifouling compounds. The compounds tested were copper pyrithione, Diuron, Irgarol 1051, KH101, Sea-Nine 211, and zinc pyrithione, all of which have been nominated in Japan as possible replacements for organotin compounds. The in vitro acute toxicity (24-h EC50) of the six compounds to these fish cells was evaluated using the dye Alamar Blue to determine cell viability, and then correlated with the results of in vivo chronic toxicities (28-day LC50) to juvenile rainbow trout Oncorhynchus mykiss. The suspension-cultured fish cells were found to be suitable for the screening of such chemicals before performing an in vivo test. The toxicities of the test compounds obtained from both tests, shown in decreasing order, were as follows: copper pyrithione > zinc pyrithione > KH101 > or = Sea-Nine 211 > Diuron > Irgarol 1051. The herbicides Diuron and Irgarol 1051 showed the least toxicity, while the pyrithiones had the greatest toxicity.     

Manganese peroxidase-catalyzed oxidative degradation of vanillylacetone

When 4-(4-hydroxy-3-methoxy-phenyl)-2-butanone (vanillylacetone) was tested for manganese peroxidase (MnP)-catalyzed oxidation, it was found to be degraded with the cleavage of an aromatic ring. Among numerous products of vanillylacetone oxidation, four major ones were purified by thin-layer chromatography and identified using mass spectroscopy (MS) and nuclear magnetic resonance (NMR) analysis. Three of them maintained the aromatic ring structure and were identified as 4-[6,2'-dihydroxy-5,3'-dimethoxy-5'-(3-oxo-butyl)-biphenyl]-butan-2-one, 4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one, and 4-[6,2'-dihydroxy-5,3'-dimethoxy-5'-(3-oxo-butyl)-biphenyl]-3-buten-2-one. Even though the fourth product could not be purified to a single compound, data from infrared spectroscopy showed that it did not have a benzene ring. From MS and NMR analysis, 3-(3-oxo-butyl)-hexa-2,4-dienedioic acid-1-methyl ester was tentatively suggested as the dominant species. The reaction mechanism was suggested on the basis of the structural information of these products. To our knowledge, this paper is the first report on aromatic ring cleavage of the phenolic compound by MnP.     

Identification of a new Irgarol-1051 related s-triazine species in coastal waters

A previously unknown s-triazine species present in commercially available Irgarol-1051, a booster biocide additive in copper-based antifouling paints for the replacement of organotin-based antifoulants, has been identified in the coastal aquatic environment. After careful isolation, purification and characterization by high resolution MS-MS and (1)H NMR, the molecular structure of that unknown species is found to be N,N'-di-tert-butyl-6-methylthiol-s-triazine-2,4-diamine (designated as M3). Levels of Irgarol-1051, its major degradation product (M1) and the newly identified M3 in the coastal waters of Hong Kong, one of the world's busiest ports located in the southern coast of China, were monitored by SPME-GC-MS and SPME-GC-FID. Water samples from five locations within Hong Kong waters were analysed and the levels of Irgarol-1051, M1 and M3 were found to be 0.1-1.6 microg l(-1), 36.8-259.0 microg l(-1) and 0.03-0.39 microg l(-1), respectively. Our results indicate that M3 is relatively stable against photo- and bio-degradation and may pose considerable risk to primary producer communities in the coastal marine environment.     

Distribution of pesticides and bisphenol A in sediments collected from rivers adjacent to coral reefs

To investigate the deteriorating health of coral reefs in Okinawa, Japan, natural sediment samples were analyzed for diuron, Irgarol 1051, chlorpyrifos, and bisphenol A (BPA) which are hazardous to corals. Samples were analyzed by solid-phase extraction (SPE) followed by high-performance liquid chromatography with tandem mass spectrometry (LC–MS–MS). Although diuron and chlorpyrifos usage is only well recorded for farms and not for cities, these chemicals were detected in both rural and urban areas. Additionally, diuron concentration in urban areas was in some cases higher than in rural areas, which might be caused by greater consumption of these chemicals in home gardens in city areas. Irgarol 1051 was detected in downstream river areas, which are situated far from the source sites such as pier or fishery harbor (0.6–3.2 km). This result suggested that Irgarol 1051 could be transported from the river mouths to the sampling sites during flood tides. High BPA concentrations were associated with urban areas (<1.2–22.0 μg kg⁻¹), while low concentrations were associated with rural areas (nd–6.8 μg kg⁻¹). The river sediments under study are delivered to coral reefs in large quantity through runoff caused by typhoons and other heavy rains. The highly hazardous chemicals are carried into coral reefs on these sediments. Therefore, these hazardous chemical substances may already be influencing the coral reefs.     

Gross fluxes and estuarine behaviour of pesticides in the Scheldt estuary (1995-1997)

As part of the Fluxes of Agrochemicals into the Marine Environment (FAME) project, the gross fluxes of selected pesticides (i.e. the herbicides atrazine, simazine, alachlor and metolachlor, the atrazine degradation product desethylatrazine, the insecticide dichlorvos and the antifouling agent Irgarol 1051) transported by the river Scheldt and the Canal Ghent-Terneuzen were determined from March 1995 through February 1997. In general, the observed temporal trends were related to the application period of the pesticides, except for metolachlor for which elevated concentrations were observed in the winter of 1995-1996. Relatively large gross fluxes were found for desethylatrazine compared with its parent compound. A study on the estuarine behaviour of pesticides showed distinct differences between the compound classes. The mixing plots of the organophosphorus insecticides dichlorvos and diazinon revealed clear evidence of estuarine loss processes which agrees with their low DT50 values reported for water/sediment systems, their relatively high Henry's law constants and, for diazinon, its relatively high Koc value. The mixing plots of the acetanilides alachlor and metolachlor were strongly influenced by an additional direct emission into the estuary, which was evident from a maximum in dissolved concentration near a salinity of 10@1000. An apparent conservative behaviour was observed for the triazine compounds atrazine and Irgarol 1051. This was in contrast to simazine, which showed an apparent non-conservative behaviour. However, the time profiles of the riverine concentrations of simazine did not exclude that the observed curvature was solely caused by estuarine losses; therefore, additional modelling is required. In a follow-up study a suitable hydrological model of the Scheldt estuary was constructed; the results will be presented in a forthcoming paper (Steen, R.J.C.A., Evers, E.H.G., Van Hattum, B., Cofino, W.P. and Brinkman, U.A.Th. Net fluxes of pesticides from the Scheldt estuary into the North Sea: a model approach. Environmental Pollution, submitted.     

Analytical methods for the determination of 9 antifouling paint booster biocides in estuarine water samples

Analytical procedures for the determination of nine organic booster biocides which are currently licensed for use in marine antifouling paints, and are thought likely to occur at concentrations in the ng 1⁻¹ range in estuarine water samples, are reviewed. A robust multiresidue method for the determination of four compounds (chlorothalonil, dichlofluanid, diuron and Irgarol 1051) is suggested. A route for the development of a method for the analysis of zinc pyrithione is outlined, based on an extraction method and subsequent derivatisation prior to determination by HPLC with fluorescence detection. Methodology for Zineb, Kathon 5287, TCMS pyridine and TCMTB is less clearly defined.     

Operation of a two-phase partitioning bioreactor for the oxidation of anthracene by the enzyme manganese peroxidase

A study was conducted to determine the potential of a two-phase partitioning bioreactor (TPPB) for the treatment of a poorly soluble compound, anthracene, by the enzyme manganese peroxidase (MnP) from the fungus Bjerkandera sp. BOS55. Silicone oil was used as the immiscible solvent, which contained anthracene at high concentrations. The optimization of the oxidation process was conducted taking into account the factors which may directly affect the MnP catalytic cycle (the concentration of H(2)O(2) and malonic acid) and those that affect the mass transfer of anthracene between the organic and the aqueous phase (solvent and agitation speed). The main objective was carried out in terms of improved efficiency, i.e., maximizing the anthracene oxidized per unit of enzyme used. The TPPB reached nearly complete oxidation of anthracene at a conversion rate of 1.8mgl(-1)h(-1) in 56h, which suggests the application of enzymatic TPPBs for the removal of poorly soluble compounds.     

Phanerochaete chrysosporium吸附载体的选择及染料降解研究

研究了游离细胞与载体吸附培养、不同载体材料对Phanerochaete chrysosporium进行连续染料脱色及产酶能力的影响。结果表明,P.chrysosporium可在载体上良好生长,甚至生长到载体内部。木屑、玉米芯、花生壳3种载体材料中,以木屑载体吸附培养物的持续脱色和产酶效果最佳,该培养物经三轮连续脱色后对染料RB5仍能达到最高95%的脱色率,并产生596 U/L锰依赖过氧化物酶（MnP）和1 326 U/L木质素过氧化物酶（LiP）,对染料的持续脱色和产酶能力明显优于游离细胞培养物。     

Applicability of microwave-assisted extraction combined with LC-MS/MS in the evaluation of booster biocide levels in harbour sediments

A new sample treatment method for the determination of four common booster biocides (Diuron, TCMTB, Irgarol 1051 and Dichlofluanid) in harbour sediment samples has been developed that uses liquid chromatography-tandem mass spectrometry (LC-MS/MS) after microwave-assisted extraction, followed by clean-up and a solid phase extraction preconcentration step (MAE-SPE). The effects of different variables on MAE-SPE were studied. The recoveries obtained were greater than 75%, and the relative standard deviation was less than 7%. The detection limits ranged between 0.1 and 0.3 ng g⁻¹. The developed methodology was successfully applied to the evaluation of the presence of booster biocides in sediment samples from different harbours and marinas of Gran Canaria Island (Canary Islands, Spain).